Injuries to riders of vehicles in which a wheel of the vehicle is a primary point of contact in a head-on collision, for example bicycles and motorcycles, are a serious concern. For example, with respect to bicycles, studies on cyclist fatalities have demonstrated that 92% of cycling fatalities occur secondary to collision with a motor vehicle, 72% of which involve a head injury (Cavacuiti). Fifty-seven percent of car/bicycle collisions are ‘head on’ in nature (Piantini), a mechanism demonstrated to be an independent risk factor for injury severity based on multinomial logit models (Kim). During a front-end collision, or even during hard braking (Bretting), a standard bicycle frame disperses kinetic energy in a manner that violently throws the rider from the frame (sometimes referred to as a “pitch-over” crash, i.e. a crash in which the rider is thrown from the bicycle), the mechanism by which cycler injury and/or death often occurs. A recent 13-year review of spinal injuries associated with bicycle accidents has stressed that ‘injury prevention needs to be a primary goal’ (Dodwell).
Typical two-wheeled vehicles such as bicycles or motorcycles have a rigid fork. Bicycles having a front suspension are known, for example for use in cross-country or downhill mountain biking. However, bicycle front suspensions are typically aimed at absorbing impacts from the front wheel running over a bump, for example a rock, log, root or other obstacle, rather than absorbing impacts from head on collisions between the bicycle and a larger, stationary object that completely halts forward movement of the bicycle. Traditional bicycle front suspensions allow the front wheel to move only in a direction aligned with the front fork of the bicycle, i.e. the suspension can retract and extend only in the plane of the front fork of the bicycle. The suspension cannot effectively absorb forces experienced during a head on collision in which the front wheel strikes another object.
Many vehicles have been designed with structures to absorb the impact of a head on collision, rather than transferring the force of the head on collision through a wheel. For example, cars and other automobiles have been designed so that the front bumper and, in a severe collision, a front portion of the body of the vehicle, will strike an object in a head on collision to absorb energy and protect the occupants of the automobile. Thus, the front wheels of the automobile are not the primary point of contact in a head on collision. However, other vehicles such as bicycles, motorcycles, some three-wheeled automobiles, wheelchairs, scooters and the like are not designed with such features, and the front wheel is often the primary point of contact with an object struck during a head on collision. There remains a need for effectively absorbing forces generated when a wheel of a vehicle strikes an object in a head on collision to minimize injury to the rider or driver of the vehicle.
The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.